New derivative of gitoxin, the use and preparation thereof



United States Patent ""ce P,..,.... Mffifiii 3 184 383 venous injection to six animals, using the Kneiiel-Lenz NEW DERIVATIVE OF GiTOXIN THE USE AND method. A valve Of 0.73 mg./ kg. has been obtained for the PREPARATIDN THEREOF pentaformylgitoxin, whereas the minimum lethal doses of Christian Arthur Hupin, Koekelherg, Brussels, Belgium, gi-taloxin and gitoxin is of 0.98 mg./ kg. and 3.073 mg./ kg. assignor t o Manufacture de Produits Pharmaceutiques 5 respectively. A comparison of these results shows clearly Chrlstlaells soclete Ammyme, Brussels, Belgium a higher activity of pentaformylgitoxin, due to a better I No Drawing. Filed Nov. 21, 1963, Ser- NO- 325,501 solubility and diifusion ability than those of gitaloxin and Claims priority application Belgium Nov. 28 1962 500 111 especially gitoxin.

8 Claims. Ths invention relates to pharmaceutical compositions 10 contanmg pentaformygitoxin as active ingredient, as well This invention relates to a new derivative of gitoxin as a pharmaceutically acceptable vehicle. having valuable pharmacological properties. This inven- The new compositions may be administered orally tion also relates to pharmaceutical compositions having a under various dosage forms such as tablets, as well as cardiotonic activity and containing, as active ingredient, parenterally and rectally. the new gitoxin derivative. This invention concerns also 1 For an initial treatment by means of tabletsor pills, a process for preparing the new gitoxin derivative. the daily dosage may be of 3 mg. ofactive ingredient.

This new gitoxin derivative is pentaformylgitoxin of Each tablet may contain, for example, 0.2 mg. of active the following formula: ingredient. After the initial treatment, a daily dosage This compound (C H O melts at 140160 C., has of 0.4 mg. of active ingredient may be given as sustaina molecular weight of 921 and a saponification index of ing treatment.

6.51 (100 mg. of pentaformyl group correspond theo- By injection, an initial dosage of 2 mg. of active inretically to 6.51 ml. of 0.1 N soda); the R of the comgredient may be sufiicient, each vial containing, for expound is of 0.85 (in the chromatography field, R is the ample, 0.5 mg. of active ingredient dissolved in an orratio of the distance between the spot of the product and ganic solvent.

the starting point to the distance between the starting For the use of the product rectally, suppositories conpoint and the solvent front). taining 0.5 mg. of pentaformylgitoxin are used.

The pentaformylgi-toxin according to this invention has This invention relates also to a process for preparing an interesting cardiotonic activity, as shown by several pentaformylgitoxin. According to the invention gitoxin pharmacological tests. is formylated in such a manner that the five hydroxy When the new derivative is included in the perfusion groups of gitoxin are formylated. In a particular emliquid of' an isolated heart of a batrachian (such as a bodiment of the process according to the invention, gifrog), 2. toning up followed by a heart failure in systole toxin is reacted with the mixed anhydride of formic occur. The graphic recording of this phenomenon gives acid and acetic acid, using an amount of anhydride at a characteristic curve of a cardiotonic substance. least equal to 170 times the stoichiometric amount of The new compound has also been introduced in the gitoxin. Preferably, an amount of anhydride of less than circulatory system of mammalians, such as cats and 390 times the stoichiometric amount of gitoxin is used. guinea pigs, and it has been found that said compound The reaction conditions depend from the amount of aninduces changes in the electrocardiogram. These changes hydride used and from the temperature of the reaction are entirely typical of digitalic impregnation. It is medium. The lower limit of the amount of anhydride is known that digitalis purpurea contains cardiotonic glunecessary for avoiding the formation of tetra-, triand cosides similar to gitoxin and gitaloxin, the action of di-formylgitoxin, whereas the higher limit of said amount which is taken as a reference. These substances, when is necessary for avoiding the production of anhydroused in controlled amounts, make the heart movements gitoxin, the presence of which is shown by fluorescence regular, but they become noxious beyond a certain conin the ultra-violet spectrum. Moreover, by controlling centration. When the injection of the new derivative is the temperature so as to maintain this temperature at a continued, the excess of said derivative produces heart 6 value not higher than room temperature, the production failure bywentricular fibrillation. of said undesired compounds is avoided.

The lethal dosis (LD of the new compound has The various gitoxin derivatives have been identified been determined on mice. This lethal dosis amounts to by upward chromatography on Schleicher Schull paper 3.7 mg./kg. when the compound is orally administered, 2043b impregnated with formamide. The elution takes whereas the lethal dosis is 3.5 mg./kg when the complace with a mixture of cyclohexane and methyl ethyl pound is given by hypodermic injection. These values ketone saturated with formamide. The following prohave been determined by the probit method on a sufficedure is used:

cient number of animals (60 for each batch). These To 100 ml. of 5:4 mixture of cyclohexane and methyl results show that the resorption is identical when the ethyl ketone, 20 ml. of formamide are added. The solucompound is given orally or parenterally. tion is stirred in a vial. Two phases are formed on stand- For determining the minimum lethal dosis on the ing. The upper phase is separated and used as eluent.

guinea pig, the product has been slowly given by intra- A R of 0.84:0.05 is found.

The fact that gitoxin'has been completely iormylatedi' may be checked. In a mixture of acetic 'anhydride and pyridine, pent-aformylgitoxin remains unchanged. This shows that the five hydroxy gr'oupsof gitoxin have been csterified. Moreover, a mild'hydrolysis in acetone gives after chromatographic separation, git-aloxigenin and shows that the OH group in the l6-position has been form-ylated.

The formyl groups have been identified'by the Fauconnet for illustrating --anhydride into 308 ml. of formic acid. The'solution is maintained at C. during 4 hours. The mixed anhydride is then added slowly at 0 C. to the pyridine sol-us tion of gitoxin. When the. addition is] complete, the

reaction mixture is maintained during 16 hours at room temperature. The reaction product is precipitated in liters of ice cooled water. and washed with water. The residue is extracted with 150 mhof chloroform and the chloroform extract is washed with Water. The organic solution is then dried on anhydrous magnesium sulphate, concentrated to a volume of 50% of the initial volume and added, drop by drop, to 1 liter of cyclohexane at 0 C." The precipitate is filtered oif and dried, so as to obtain 9.5'grams of pentaformylgitoxin (melting point;- 140l60 C.; this The precipitate is filtered ofi.

When

The solution is cooled on a ice bath 7 a pharmaceutical excipient solution.

4.. containing milk sugar, rice starch, potato starch, gum-acacia and talc.

EXAMPLE 5 a cardio tonic action and consisting essentially of pentarformylgitoxin, as active ingredient, and a tablet forming carrier therefor, said tablet containing 0.2 milligram of r j the pen-taforrnylgitoxin per 100 grams of tablet.

melting point is diificult to measure, even after several 7 1 Determined by the Signer'method. t 2 Number of ml. of N aOH corresponding 110100 mg. of pentaformylgi OXID- Chromatographic tests have shown that the Rf is of precipitatious). The .following tables gives other char-.-

acteristics of the obtained product, compared to the thee-- retical values.

Table I CHO Molecular Saponifi- C H groups weight 1 cation index Theoretical va1ues 59.98 7.00 15.75 921 6.61 Found values 60. 39 7.12 15. 74 951- 6. 34

3. A pharmaceutical composition in the form of a unit dosage vial for injection, said vial consisting essentially of 0.5 mg. of pentaformylgitoxin in solution in 0.5 milliliter of a 4:1 mixture of tertiary butanol and acetone, said solution being diluted with 4.5 milliliters of physiological saline solution to yield a composition having cardiotonic action.

4. 'A pharmaceutical composition in suppository form having a ca'rdiotonic action and consisting essentially of pentaformylgitoxin, as active ingredienhand a suppository-forming carrier therefor, said suppository containing 0.5 milligram of the pentatformylgitoxin per 2 grams of suppository. V

5. A process for preparing pentaformylgitoxin, in

which gitoxin isreacted with themixed anhydride of forniicacid and acetic acid until the five hydroxy groups 40 hydride of at least 170 times the stoichiometric amount of gitoxin. i V

6. A process for preparing pent-aformylgitoxin, in which gitoxin'is reacted with the mixed anhydride of formic acid and acetic acid until the five hydroxy groups of .the gitoxin are esterified, using an amount of said anhydride comprised between 170 and 390 times the stoiohiometric amount of gitoxin.

. 7. A process for preparing pentaformylgitoxin, in which gitoxin is reacted at a temperature at most equal, to room 0.84 and .that traces of tetraformylgitoxin (R =0.45) are contained'in the product.

EXAMPLE 2 The method describedin examplel is used, except that 286 milliliters'of acetic anhydr-ide and 398 milliliters of EXAMPLE 3 The method described in. Example 1 is used, except that 326 milliliters of acetic anhydride and-490 ml. of formic acid are reacted. When the reaction is complete,

7 the reaction mixture is treated with 20 liters of ice cool water. V a

Chromatographic tests show a R 0.84. Theobtained 'pentaformylgitoxin is pure.

EXAMPLE 4 Tablets (weighing milligrams) containing each 0.2

milligram of pentatormylgitoxin have been prepared with pyridine.

I temperature with the mixed anhydride of formic acid and acetic acid until the five hydroxy groups of the gitoxin are esterified, using an amount of said anhydr-ide of at least times the stoiohiometric amount of gitoxin, the reactants being dissolved in pyridine.

8. A process for preparing pentaformylgitoxin, in which gitoxin is reacted at a temperature at most equal to room temperature with the mixed anhydride of. formic acid and acetic acid until the five-hydroxy groups'of the gitoxin are esterified, using an amount of said anhydride comprised between 170 and 390 times the stoichiomet-ric amount of gitoxin,

the reactants. being dissolved in ReterencesCited by the Examiner UNITED STATES PATENTS 2,395,337 2/46 Marker etlal e 260-2105 3,023,147

OTHER REFERENCES Pigman: The Carbohydrates, 1957, pp. 139-142,

' Academic Press Inc., New York, New York.

Ringold et al.: LAmer. Chem. Soc, vol. 78, Feb. 20, 1956, pp. 816-825.

LEWIS GCTTS, Primary Examiner. 

2. A PHARMACEUTICAL COMPOSITION IN TABLET FORM HAVING A CARDIOTONIC ACTION AND CONSISTING ESSENTIALLY OF PENTAFORMYLGITOXIN, AS ACTIVE INGREDIENT, AND A TABLET-FORMING CARRIER THEREFOR, SAID TABLE CONTAINING 0.2 MILLIGRAM OF THE PENTAFORMYLGITOXIN PER 100 GRAMS OF TABLET. 